API Authorization
Authorization is a critical security process that determines whether a Client or User has the necessary permissions to access a specific resource or perform an action within an API. While Authentication verifies identity, authorization focuses on the scope of access granted to that identity. In modern distributed systems, this is often managed through centralized Identity Providers.
The industry standard for delegating API Security is OAuth 2.0, which utilizes Access Tokens to communicate permissions. These tokens often take the form of JSON Web Tokens (JWT), which contain claims about the user's Scopes and roles. Detailed specifications for these protocols can be found at the Official OAuth Website and within IETF RFC 6749.
Common methodologies for implementing authorization include Role-Based Access Control (RBAC), where permissions are tied to defined roles, and Attribute-Based Access Control (ABAC), which offers more granular control by evaluating attributes of the user, resource, and environment. Effective authorization prevents vulnerabilities such as Broken Object Level Authorization (BOLA), a frequent entry on the OWASP API Security Top 10.